The field of the invention relates generally to electric motors, and more particularly, to a motor control system having a remote power supply module for stepping down line voltage to a rated DC voltage and a method of use.
Electric motors are utilized in various fluid handling applications, including heating, ventilation, and air conditioning (HVAC) appliances (furnaces, heat pumps, and air conditioners). For example, an electric motor drives a rotating component (e.g., a fan, blower, or impeller) to generate a fluid flow through an appliance. Many known electric motors include a motor control assembly that contains various electronic components for conditioning power for the electric motor, controlling the electric motor, and carrying out communication between the electric motor and other components of the appliance. Typical motor control assemblies are large relative to the electric motor itself, sometimes extending the length of the motor assembly by as much as 50%. Such motor control assemblies can impede fluid flow, which reduces efficiency and increases the cost of operating and maintaining the electric motor.
In addition, electric motors operate in locations having respective power sources with differing voltages available. For instance, in North America, three common input line voltages available to power HVAC motor controllers are 230V, 460V, and 600V (±5-15%). Various spacing, sizing, and rating standards apply to motor controllers based on the input line voltage, and, generally, motors that are powered with higher line voltages are larger and more expensive to build and to purchase. Accordingly, motors that are rated for certain applications cannot be powered with line voltages above a particular level. In such situations, the end users of the motor must either implement larger and more expensive motors that accept the higher input line voltage, or must purchase and install transformers to step-down the line voltage. Such transformers, however, can be expensive, bulky, and inefficient.